In article <hhhmhl$o48$1 at smc.vnet.net>,
Valeri Astanoff <astanoff at gmail.com> wrote:
>
> Imho, when applying a rule lhs -> rhs
> it's a risky practice to use the same symbol
> in 'lhs' and 'rhs', because, very often, there is
> no easy way to check what has been done.
>
> Anyway, for occasional users, you're right : it's crazy!
>
Thank you -- that's really my primary point.
And I'd add: it's damaging (to users, and to Mathematica).
As for writing rules, I'd not even try writing something compound, like
a + b or especially something like 1 + I, on the lhs, because I'd have
no intuition as to how this would work (how spaces would be handled,
etc.)
But a single character on the lhs? It works correctly AFAIK for every
other single-character in the alphabet. Why shouldn't one expect it to
work for I?